The City of Ottawa's manager of environment services last week overstated the amount of waste Plasco Energy Group had processed this year, according to a memo he sent to councillors Thursday.

Dixon Weir told the city's environment committee Nov. 20 that the garbage-processing company had processed 7,000 tonnes so far in 2012.

On Thursday, he sent a clarification.

Plasco's waste-to-energy plant is still in the demonstration phase and has yet to handle volumes of garbage called for in the company's agreement with the city. (Plasco Energy Group)

"Upon further review of the data, 6780 tonnes were delivered to Plasco in 2012, which I rounded up to 7000 at the Committee meeting. Plasco returned 3200 tonnes to Trail Landfill for disposal. As a result, Plasco processed 3600 tonnes in 2012, as of mid-September," wrote Weir.

Last year the city came to an agreement in principle to have Plasco take on 300 tonnes a day of residential waste at a cost of $83.25 per tonne to local taxpayers.

But the deal is contingent on Plasco completing construction of its waste-processing plant by 2016 and securing financing by 2013.

Plasco uses a process called plasma gasification that uses electrical energy and the high temperatures to break down waste, primarily into elemental gas and solid waste. But the technology has not been proven to work on a large scale.

Plasco's demonstration facility is still in what they're calling a "campaign" phase, and hasn't operated in a sustained manner.

The 7,000-tonne figure Weir referred to last week represented a significant boost in production from previous years.

The city is "very close" to finalizing a contract with Plasco and is expected to have one signed by mid-December, said environment committee chair Maria McRae after Weir made his presentation last week.